Well packers and anchoring means therefor



Aug. 30, 1955 R. K. LE ROUAX n 2,716,457

` WELL PACKERS AN D ANCHORING MANS THEREFOR Filedpt. 2, 195o e sheets-'sheet 1 MY WMYM/ BL/ am@ jv @uw ATTO/Mfrs Aug. 30, 11955 R. K. LE RoUAx 2,716,457

WELL PACKERS AND ANCHORING MEANS THEREFOR Filed sept. 2, 195o 6 Sheets-Sheet 2 Robe/ A. @Hoc/0A* JNVENToR. l

CMAJ

. ATTORNEKS Allg. 30, 1955 R. K. LE RoUAX 2,716,457

WELL PACKERS AND ANCHORING MEANS THEREF'OR Filed Sept. 2, 1950 6 Sheets-Sheet 3 Lev Robe/ K. e/ouox INVENTOR.

ATTORNEYS Aug. 30, 1955 fia/7 R. K. LE ROUAX WELL PACKERS AND ANCHORING MEANS THEREFOR Filed Sept. 2, 1950 6 Sheets-Sheet 4 Rober A. eRoc/Qx INVENTOR.

A TTO/WVEYS Aug. 30, 1955 R. K. I E RoUAx 2,716,457

WELL PACKERS AND ANCHORING MEANS THEREFOR Filed Sept. 2, 195C 6 Sheets-Sheet 5 A r rom/E ys Aug! 30, 1955 R. K. LE ROUAX 2,716,457

WELL PACKERS AND ANCI-.IORING MEANS THEREFOR Filed Sept. 2, 195C 6 Sheets-Sheet 6 United States Patent O WELL PACKERS AND ANCHRING MEANS THEREFOR Robert K. Le Rouax, Houston, Tex., assigner to Oil Center Tool Company, Houston, Tex., a corporation of Texas Application September 2, 1950, Serial No. 182,906

Claims. (Cl. 16d-13u) This invention relates to new and useful improvements in well packers and anchoring means therefor.

One object of the invention is to provide an improved well packer which is adapted to be set or anchored within the Well without the necessity of imparting rotation to the tubing or supporting string on which the packer is mounted.

An important object of the invention is to provide a well packer having a latching means associated with its anchoring mechanism for normally latching the anchoring mechanism against operation to permit lowering of the packer to the desired position within a well bore, said latching assembly being movable to an inactive or unlatching position by a coacting means formed on the tubing or supporting string, whereby relative movement between the tubing and the latching assembly controls the operation of said assembly.

Another object of the invention is to provide an improved well packer which may be set within a well bore solely by the application of fluid pressure through the annulus between the tubing and the casing and without any movement of the tubing or supporting member on which the packer is mounted.

Still another object is to provide an improved packer which is so arranged that it may be set and released merely by a longitudinal movement of the well tubing or supporting string and without the necessity of rotating said tubing or string so that the disadvantages of rotation are eliminated.

A further object is to provide an improved anchoring means for a well packer or other well tool which includes anchoring slips and latching arms for normally latching the slips to the tubing or supporting string in a position which prevents operation of the anchoring means; the device including xed projections or surfaces on the tubing or supporting string which coact with the latch members upon relative movement of the supporting string with respect to the latch means to thereby control actuation of said latch means.

Still another object is to provide a packer of the characI ter described which is constructed so that the latch means is automatically maintained in an inactive or non-latching position at the time that the anchoring slips are in a set position.

The construction designed to carry out the invention will be hereinafter described together with other features thereof.

The invention will be more readily understood from a reading of the accompanying drawings forming a part thereof, wherein an example of the invention is shown, and wherein:

Figure 1 is an elevation of a well packer constructed in accordance with the invention and illustrating the same being lowered within a well casing,

Figure 2 is a similar View showing the packer in a fully set position,

Figure 3 is a view partly in section and partly in eleva tion of the upper portion of the well packer and showing ICC the packer elements in the position which they assume during lowering of the device within a Well casing,

Figure 4 is a continuation of Figure 3 illustrating the intermediate portion of the packer, f

Figure 5 is a continuation of Figure 4 showing the lower portion of the packer and clearly illustrating the latch means in its latched position,

Figure 6 is a horizontal cross-sectional View taken on the line 6 6 of Figure 4,

Figure 7 is a horizontal cross-sectional view taken on the line 7 7 of Figure 5,

Figure 8 is a fragmentary view in section and illustrating the latching means in position disengaging the tubing or supporting string,

Figures 9 and 10 are views partly in section and partly in elevation showing the well packer in its fully set position,

Figure ll is a horizontal cross-sectional View taken on the line 11-11 of Figure 10,

Figure 12 is a view similar to Figure l of a modified form of the invention,

Figure 13 is a View similar to Figure 12 illustrating the modication of the invention in its fully set position,

Figure 14 is a view partly in section and partly in elevation of the intermediate portion of the modified form illustrated in Figures l2 and 13,

Figure l5 is a continuation of Figure 14 of the lower portion of the modied form,

Figure 16 is a horizontal cross-sectional view taken on the line 16-16 of Figure l5, and

Figure 17 is a view partly in section and partly in elevation illustrating the modified form of the invention in its fully set position.

In the drawings, the numeral 10 designates a well pipe or casing which is disposed within a well bore A and within which the improved well packer is adapted to be set or anchored. The packer is adapted to be lowered on an inner pipe or tubing string 11 and the tubing forms the sole support for the packer, whereby the same may be lowered and raised within the well casing.

As is clearly shown in Figure l, the well packer includes a packer assembly B at its upper end, an anchoring unit mechanism C at its intermediate portion and a latching assembly D at its lower portion. The latching assembly D, as will be hereinafter explained, is arranged to normally lock the anchoring mechanism C against actuation whereby the packer may be lowered into the well casing 10 to the desired position therein. When the latching assembly is operated, the anchoring mechanism C is released for actuation and may be set, after which the packer assembly may be expanded to pack olf between the inner supporting string or tubing 11 and the well casing 10. The arrangement is such that when it is desired to remove the packer, it is only necessary to pull upwardly on the inner supporting string or tubing 11 and this will result, as will be explained, in the packer assembly B and the anchoring mechanism C being released so that the entire unit may be removed from the well casing. It is pointed out that the structure is such that rotation of the inner string or tubing 11 which supports the well packer is unnecessary to either set the anchoring mechanism or release the same.

Referring to Figures 3 to 5 the inner supporting string or tubing 11 has a valve head 12 connected therein and said head is formed with a seating surface 13 which may have an annular packing ring 14 mounted therein. A section 11a of the tubing extends downwardly from the valve head 12 and projects entirely through the well packer. At its lower end the section 11a has a coupling collar 15 threaded thereon and a tail pipe 16 extends downwardly from the collar.

The packer assembly B includes a tubular mandrel18 (Figure 3) which surrounds the upper portion of the tubing section 11a and the upper end of the mandrel has an annular valve seat member 19 secured thereto. The member 19 is formed with an inclined seat 2t) which is adapted to be engaged by the seating surface 13 of the valve head. The bore of the mandrel 1S is of larger diameter than the external diameter of the tubing section 11a whereby a flow passage 21 is provided between the mandrel and the tubing section. A pair of superposed packing sleeves 22 surround the mandrel and have flanged retaining collars 23 confining the upper and lower ends of said packing sleeves. The lower retaining collar of the lowermost packing sleeve engages the upper end of a tubular perforated section 24 which section encircles the tubing 11a in spaced relationship thereto. The perforated section 24 having a plurality of radial perforations 25 is connected to the lower end of the mandrel 18 by a shear pin 26, and thus the packing elements 22 are conned on the mandrel 18 between the upper valve Seat member 19 which is secured to the upper end of the mandrel, as by welding 19a, and the perforated tubular section 24. The external surface of the packing elements 22 is normally of a diameter less than the bore of the well casing 10, and thus, so long as the shear pin 26 connects the mandrel to the perforated section 24, distortion of the packing elements cannot be effected.

The tubular perforated section 24 which encircles the Supporting tubing 11a has its lower end welded or otherwise secured to an expanding cone 27 which surrounds the section 11a (Figure 4) and said cone is normally attached to the section 11a by a shear pin 28. lt is noted that the shear pin 25 is of lesser strength than the shear pin 26 whereby the pin 28 will shear under a lesser weight than will the upper shear pin. The expander cone 27 has 'its lower end engaging an external shoulder 29 which is formed on the tubular supporting section 11a.

The slip expanding cone 27 is adapted to coact with gripping slips 36 and these slips have been illustrated as three in number although, of course, any desired number may be employed. Each slip is arcuate in crosssection and has gripping teeth 31 formed on its external surface. The lower portion f the inner surface 32 of each slip generally conforms to the external surface of the Supporting tubing section 11a while the upper portion of the inner surface of each slip is inclined or tapered as indicated at 33; the tapered portion 33 of the inner portion of each slip is adapted to coact with the inclined outer surface of the expander cone 27 when the expander cone is moved downwardly between the slips as illustrated in Figure 9.

For limiting the extent of expansion of the slips by the cone the lower portion of each slip is formed with an internal groove 34 which receives a stop ring 35- (Figure 4):. The bore or opening through the stop ring 35l is of a diameter which is larger than the exterior of the section 11a but is less than the external diameter of the lower end Zia of the expander cone. Thus, when the expander cone is moved downwardly within the slips di)A as shown. in Figure 9 the slips are moved. outwardly into engagement with the bore of the well casing AV and the movement of the cone within the slipsA is limited by the engagement of the lower end 27a of said cone with the stop ring 3S.

Each gripping slip 33 is connected by a flexible strap 37 with the upper end of a collar 38 which is formed at the upper end of the latch assembly D. The collar 33 has. a piston cup 39 mounted therein and said cup is provided with an upwardly directed sealin g lip 39a whereby pressure from above said cup will tend to urge the cup and the collar 3'8 to whichit is attached downwardly.

A plurality of latch arms 4i) each have their upper ends secured to the collar 38 and are in effect suspended from said collar and: are disposed in spacedy relationship around the exterior of the tubing section 11a; Each-latch arm includes an. elongate relatively flat strap which has CTL lli

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an inwardly directed latching dog 41 located intermediate its ends. As is clearly shown in Figure each latch dog has an inclined inner surface 42 and an upper surface 43 which forms an inwardly directed shoulder on the inner surface of the latch arm.

ln order to permit coupling or connection of the latch arms 46 with the tubing section 11a an elongate tubular sleeve 44 surrounds the section 11a (Figures 4 and 5) and has its upper end welded at 44a with its lower end welded at 44b to said section. The extreme lower end of the sleeve 44 is formed with an external ange 45 which functions as a stop or supporting shoulder as will be hereinafter explained, Since the elongate sleeve 44 is welded or otherwise secured to the tubing section 11a, it is in effect a part of said section.

The external surface of the elongate sleeve 44 is adapted to coact with the latch arms 40 to effect the actuation of said latch arms and as is clearly illustrated in Figure 5 the upper portion of the sleeve 44 is formed with an annular groove or recess 46. This recess has an inclined surface 47 generally complementary to the inclination 42 of each latching dog 41; an overhanging shoulder 48 adapted to be engaged by the inwardly directed shoulder 43 of each latch arm is provided in the recess 46. lt will be evident that when the dogs 41 of the latch arms 49 are engaged within the annular recess 46 a downward movement of the tubing section 11 and the sleeve 44 attached to said section will result in a downward movement of the latch arms and of the col-lar 33 to which the upper end of said arms are attached. As explained, the collar 38 has connection through the straps 3-7 with the gripping slips 36 and thus when the latch arms are engaged within the groove 46 the tubing string and the gripping slips will be moved downwardly as a unit. Since the expander cone 27 is supported upon the shoulder 29 and is also connected to the tubing section 11a through the shear pin 28, it will be apparent that downward movement of the assembly through the well casing may be accomplished without danger of the gripping slips being moved upwardly into the engagement with the expander cone. The latch arms thus function to latch the gripping slips in a position on the tubing section 11a which will prevent expansion or setting cf said slips.

An annular cup unit is slidable upon the lower end of the sleeve 44 and includes a collar 49 having a pistonl cup Si! mounted thereon; the sealing lip 50a of they sealing cup is directed downwardly whereby fluid pressure present in the annular space between the tubing andthe casing will tend to slide the cup uni-t upwardly on the sleeve to the position shown in Figure 5. In such position the upper end of the collar 49 engages the lower extended ends of the latch arms 40. To permit a. by-pass of fluid around the lower cup 50- whenthe parts are in the position shown in Figure 4 during lowering of a packer within a casing, the external surface of the elongate sleeve 44 is formed with by-pass grooves 51 which span the collar 49. With this arrangement af free by-pass of fluid around the cup 50 may occur during lowering of the device into the well casing.

For swinging the latch arms 40 outwardly so that their respective latching dogs 41 will disengage the annular locking groove or recess 46, the sleeve 44 has its lower portion enlarged as indicated at 52 and this enlarged por tion is merged into the external surface of the upper portion of the sleeve by an annular inclined cam surface 53. It will be evident that when the latching arms 40 undergo a relative movement with respect to the tubing section 11a and its attached sleeve 44 in' a direction which will move the sleeve 44 upwardly with respect tothe arms, the inclined cam surface 53 will engage the inclined surfaces 42 of the latching dogs and will cause an outward swinging of the lower end of the latch arms. This swinging movement will be sucieut to cause the lower edge 40u of each latch arm to clear the upper endl of the collar 49 of the lower cup unit so that the collar 49 may be moved upwardly with respect to the latch arms whereby the lower portions of the latch arms mayl overlie the external surface of the collar, as shown in Figure 8. Upward movement of the collar 49 relative to the latch arms is limited by an external shoulder 49a formed on the collar 49 above the sealing cup 50. It is therefore apparent that the cam surface 53 and the enlarged lower end 52 of the sleeve 44 will function to swing the lower end of each latch arm outwardly to permit the collar 49 to be engaged beneath the latch arms and said collar will thereby function to maintain the latch arms in their outer position. ln such outer position the latching dogs 41 are clear of the annular groove or recess 46 and so long as the collar 49 remains beneath the lower ends of the latch arms, a reengagement of the latching dogs with the groove is not possible. Under such conditions, the latching assembly which includes the lower cup 50, the latch arms 4i), the upper cup 39 and the gripping slips may be moved relative to the tubing section 11a Or the tubing section may be moved with respect to the latching assembly. The slips 30 may therefore be moved upwardly into contact with the expander cone so as to set or lock the slips within the casing and the position of the parts at this time is illustrated in Figures 9 and 10.

It is desirable that provision be made for closing the by-pass opening 51 at certain times in the operation and for this purpose a sealing sleeve S4 is provided. This sleeve encircles the enlarged portion 52 of the elongate operating sleeve 44 and the latch arms 40 extend through vertical external grooves 55 formed in the sealing sleeve. The sleeve is confined against longitudinal displacement with respect to each latch arm by arcuate stop elements 56 which are welded or otherwise secured to the inner surface of each latch arm. The stop elements 56 confine the sleeve in a particular longitudinal position on each latch arm while permitting a radial movement of the latch arms with respect to the slip. The sleeve 54 is adapted to cover the by-pass grooves 5.1 which are provided in the external surface of the sleeve 44 under certain conditions of operation of the device.

In the operation of the packer the parts are assembled as illustrated in Figures 3 to 5 and in this position the shear pins 26 and 28 are connecting the packing assembly B with the section 11a. The latch arms 40 have their dogs 41 engaged with the annular recess 46 in the sleeve 44 and the slips are thereby latched against upward movement on the tubing section 11a. At this time the lower cup 50 is in the position shown in Figure 5 and a free by-pass of fluid around the cup is permitted through the by-pass grooves 51. As the tubing 11 and its connecting section 11a are lowered downwardly through the well casing 10, all of the parts remain in the same relative positions shown in Figure l and setting of the slips is impossible because of the connection between the latch arms and the latching recess 46.

When the position at which the packer is to be set is reached a fluid pressure is applied downwardly through the casing in the annular space between the tubing 11 and said casing, and at the same time the tubing string is held stationary. The application of pressure to the upper cup 39 moves the latching assembly downwardly with respect to the tubing and this causes the latching dogs 41 of the latch arms 40 to ride downwardly out of the groove 46 and along the external surface of the tubular sleeve 44. Upon contacting the cam surface S3 the dogs 41 function to impart an outward swinging or radial movement to the lower ends of the latch arms, whereby the lower edge each latch arm swings clear of the upper end of the collar 49 of the lower cup unit. This position of the parts is illustrated in Figure 8, and at this time the sealing sleeve 54 has moved opposite the by-pass grooves 51 to close the same.

The pressure being applied through the annular space between the tubing and the casing is then reversed with a greater pressure being applied to the lower packing cup 50. This causes the lower packing cup to move upwardly between the lower ends of the latch arms 40 and will prevent the latch arms swinging inwardly until such time as the collar 49 again moves from therebeneath. The lower edges 40a of the latch arms are thus moved into contact with the shoulder 49a of the collar 49 and z the continued application of pressure from below will slide the latching assembly and the gripping slips 30 upwardly with respect to the tubing section 11a. Because the latch arms are being maintained in an outward position with the dogs 41 of said arms clear of the locking recess 46 the latching assembly may move upwardly to the position shown in Figure l0, and this moves the slips 30 upwardly along the expander cone 27 whereby said slips are lirmly locked in position within the casing. It is therefore obvious that the slip mechanism may be set solely by uid pressure and the tubing string remains stationary during the entire setting operation.

After the slips have been set the weight of the tubing is imposed upon the shear pin 28 to shear same to disconnect the cone 27 from the tubing. Continued application of weight will then shear the pin 26 to disconnect the mandrel 18 of the packing assembly from the perforated section 24 which is supported by the cone and thereafter the valve 12 may be seated within the valve seat member 19 to close the by-pass 21 through the packer and to subsequently expand the packer sleeves 22 to the position shown in Figure 9. It is noted that if desired a washing operation may be carried out prior to the shearing of the pin 26 and while the valve head 12 is still above or out of engagement with the valve seat member 19.

When it is desired to remove the packer from the well casing it is only necessary to move the well tubing upwardly whereby the valve head 12 is disengaged from the seat member 19. This relieves the pressure upon the packing sleeves 22 and permits their retraction. Continued upward movement of the tubing will cause the cone 27 to be picked up by the shoulder 29 so as to move the cone from between the slips 30. The spring arms 37 which carry the slips will then retract said slips. The latching assembly will thereafter move downwardly on the tubing section until the collar 49 of the lower packing cup unit engages the pick-up or stop shoulder 4S at the lower end of the tubular sleeve 44 and thus, the entire unit may be released and withdrawn from the well without the necessity of rotating the tubing string.

As described above, the setting of the slips 30 may be accomplished solely by fluid pressure acting rst on the upper end of the latching assembly and then acting upon the lower end thereof. In some instances, it may be desirable to set the slips by a longitudinal movement of the tubing string. In such case, assuming the parts to be in the position shown in Figures 4 and 5 with the dogs 41 of the latch arms engaged in thel locking recess 46, the device is lowered to the position at which it is to be set. At this point the tubing and its section are pulled upwardly and the latch arms are mantained stationary in the casing by the frictional engagement of the upper piston cup 39 with the bore of the casing. Any pressure acting below the cup 50 will hold the collar 49 of the lower cup unit engaged with the lower edge 40a of each latch arm.

As the tubing is pulled upwardly the cam surface 53 on the sleeve 44 is engaged with the latch dogs and functions to swing the lower end of the latch arms outwardly and clear of the upper edge of the collar 49. When this occurs the pressure below the lower cup 50 will immediately move said cup upwardly between the latch arms to hold them in their expanded or inactive positions. Thereafter the tubing may then be lowered and thelocking recess 46 will clear the latching dogs 41 so that the expander cone 27 may be moved into the gripping slips 30 to expand the same. Thereafter, the setting of the packer sleeves 22. will be as herein described.

From the foregoing, it will be evident that the packer is arranged so that the anchoring mechanism may be moved to a set position solely by the application of fluid pressure which is applied tirst to the upper cup to move the latching assembly downwardly to release the latch dogs and then upwardly to move the slips into contact with the expander cone. If desired, the slips may be set solely by manipulation of the tubing and in such case the tubing is first moved upwardly with respect to the latch arms to release the latch arms and lock them in their inactive position, after which the tubingis then lowered to effect a setting of the anchoring mechanism.

In some instances, it may not be desirable to provide the piston cups on the latching assembly and in Figures 12-17 such an arrangement is illustrated. ln the modiiication the upper structure which includes the packing assembly B and the anchoring unit C is identical, the only change being in the latching assembly D. As is clearly shown in Figure 14, the exible straps 37 of the slips 30 are connected to the upper end of a collar 60 and latch arms 14) have their upper ends connected to this collar. The tubular actuating or control sleeve 44 is secured to the section 11a in the same manner as in the first form and its locking recess 46 is arranged to coact with latching dogs 141. Instead of the lower ends of the latch arms being completely free the lower ends of the latch arms 140 are slotted as indicated at 142 (Figure 15) and are conned by headed bolts 143. Each boit extends through one of the slots and is threaded into the upper portion of a tubular body 144 which forms the main portion of a friction spring assembly. The friction spring assembly includes spring-pressed friction shoes 145 which ride upon the inner surface of the well casing.

When the latching dogs 141 of the latch arms 140 are engaged with the locking recess 46 of the sleeve 44 the lower edge 140a of each latch arm overlies an external shoulder 146 formed on the tubular body 144. This position of the parts is illustrated in Figure l and with the arms 140 latched to the sleeve 44' the packer may be lowered within the well casing.

When the packer is to be set the tubing section 11a is moved upwardly to engage the cam surface 53 of the sleeve 44' with the dogs 141 and such engagement will swing the lower ends of the arms outwardly to the position shown in Figure 17 whereby the lower ends 141m of the arms clear the shoulder 146 and become aligned with a second shoulder 147 on the body 1544. The tubing section 11a may then be moved downwardly and the locking recess will clear the latching dogs which are maintained outwardly because the lower ends of the arms are confined against the surface of the body 144 between the shoulders 146 and 147. This allows the expander cone 27 to be moved downwardly between the' slips 3% to set said slips. The provision of the slot and bolt connection in the lower end of each latch army permits a longitudinal movement of the arm with respect to the friction assembly and also allows radi'almovement of the lower ends of said latch arm. In the modifiedform the sleeve 44' does not have the pick-up shoulder 4S" of the rst form but the pick-up of the unit is eiected by an enlarged collar a which is connected to the lower end of the section 11a. It will be evident that the form of the invention shown in Figures 1l to 17 has all of the advantages of the rst form except that it is set and released solely by longitudinal movement or" the tubing string.

From the foregoing it will be seen that this invention is one well adapted to' attain all of the ends and objects hereinabove setV forthk togetherwith other advantages which are obvious and which are inherent to the structure.

Itwill be understood that certainl features and subcombinations are of utility and may be employed with- 8 out reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.

As many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as iliustrative and not in a limiting sense.

Having described the invention, l claim:

l. A well packer including, a support, a resilient annular packing element on the support, an anchoring unit for anchoring the packer to a well Casing including casing gripping members mounted on the support with the gripping members being slidable on said support, latching means attached lo the gripping members and exposed exterioriy of the support, means on the support engageable by the iatching means for latc'hing the gripping members and atching means against upward movement on said support, and a projection secured on the support and disposcd below the point of connection between the latching means and support, said projection engaging the latching means when the support is moved upwardly relative to the anchoring and latching means for releasing said latching means to disconnect it from said support, and means on the anchoring unit for maintaining the gripping members and latching means stationary relative to the support during the releasing of the latching means to disconnect same from said support.

Z. A well packer as set forth in claim l, together with a coiiar slidable on the support below the latching means and engageable with the latching means when the latter is moved to a released position to retain said latching means in such released position.

3. A well packer as set forth in claim l, together with a pressure-responsive member' secured to the latching means and surrounding the support, whereby pressure applied to said member will impart movement to the latching means and the gripping members which are attached thereto.

4. A well packer including, a support, a resilient annular packing element on the support, an anchoring unit assembly below the packing element also mounted on the support for anchoring the packer to a well casing and including casing gripping slips slidable on the support, said gripping slips being moved into gripping position by an upward movement of the slips relative to the support, said support having an annular locking recess in its external surface, latching elements attached to the gripping slips and having latching dogs adapted to engage the locking recess in the support for latching the gripping slips against upward movement with respect to said support, means connected with the latching elements and engageable with the well pipe in which the packer is lowered to maintain the latching elements stationary in' the pipe to allow relative movement of the support with respect to said elements, and a projection formed on the external surface of the support below the locking recess for engaging the latching elements when the support is moved upwardly relative to the latching' elements to swing said latching elements outwardly of the support, whereby the dogs of said elements will clear the locking recess and thereby permit a subsequent upward movement of the latching elements with respect to the support.

5. A well packer asv set forth inclaim 4, together with an annular retaining member sl'idable on thesupport' and normally positioned below the latching elements, said retaining member being movable upwardly betweeny the latching elements and theV support for retaining said' latching elements in an outward position after said latching elements have been moved to such outward position' by the projection.

6. in an anchoring mechanism for a well tool, a' support, an expander cone mounted on the support, gripping: slips slidably mounted on the support below the coneV and engageable with the cone upon an upward movement of the slips with respect to the support for anchoring the well tool to a Well pipe, frictional wall engaging means secured to the gripping slips, movable latch means secured to the slips and including means to detachably fasten said latch means to the support for latching the` slips against upward movement on the support in a position spaced from the expander cone, and an annular projection secured to the support and adapted to engage the latching means when the latching means and slips are moved downwardly relative to the support to move the latching means from its connected position to disconnect said latching means from the support.

7. The anchoring mechanism for well tools as set forth in claim 6, together with a collar slidable on the support below the latching means and adapted to engage beneath the latching means when the same has been disconnected from the support by the projection, said collar maintaining the latching means in a position disconnected from the support.

8. The anchoring mechanism for well tools as set forth in claim 6, together with a collar slidable on the support below the latching means and adapted to engage beneath the latching means when the same has been disconnected from the support by the projection, said collar maintaining the latching means in a position disconnected from the support, a piston cup surrounding the support and secured to the latching means andgripping slips and facing in an upward direction whereby iluid pressure applied against the cup from above may move the latching means downwardly relative to the support, and a second piston cup surrounding the support facing downwardly and secured to the slidable collar whereby pressure from below said cup may move the collar upwardly on the support and into a position beneath the latching means.

9. A well packer adapted to be lowered within a well pipe and including, a support having means for connecting it to a lowering pipe, a packing element mounted on the support and distortable radially outwardly into sealing engagement with the well pipe, an anchoring unit assembly mounted on the support for anchoring the packer to the well pipe and including anchoring means slidable with respect to the support, said anchoring means being actuated by an upward movement of the anchoring means with respect to the support to anchor the packing element within the well pipe, latching means initially connecting the anchoring means to the support to latch the anchoring means against upward movement relative to the support while permitting downward movement of said anchoring means with respect to the support, releasing means secured to the support and engage-l able with the latching means when the anchoring means is moved downwardly relative to the support to disconnect said latching means and thereby allow subsequent upward movement of the anchoring means with respect to the support whereby said anchoring means may be actuated, and a uid pressure responsive member attached to the latching means whereby fluid pressure applied to said member imparts movement to the latching means and anchoring means with respect to the support.

l0. A well packer including, a support, a resilient annular packing element on the support, an anchoring unit assembly below the packing element also mounted on the support for anchoring the packer to a well casing and including casing gripping slips slidable on the support, said gripping slips being moved into gripping position by an upward movement of the slips relative to the support, said support having an annular locking recess in its external surface, latching elements attached to the gripping slips and having latching dogs adapted to engage the locking recess in the support for latching the gripping slips against upward movement with respect to said support, a projection formed on the external surface of the support below the locking recess for engaging the latching elements when the support is moved upwardly relative to the latching elements to swing said latching elements outwardly of the support, whereby the dogs of said elements will clear the locking recess and thereby permit a subsequent upward movement of the latching elements with respect to the support, an annular retaining member slidable on the support and normally positioned below the latching elements, said retaining member being movable upwardly between the latching elements and the support for retaining said latching elements in an outward position after said latching elements have been moved to such outward position by the projection, a sealing cup secured to the latching elements and surrounding the support whereby fluid pressure from above the cup will impart downward movement to the latching elements and gripping slips relative to the support, and a second sealing cup secured to the annular retaining member and adapted to seal against fluid pressure from below, whereby said pressure from below will act against said second sealing cup to move the retaining member upwardly on the support with respect to the latching elements.

References Cited in the file of this patent v UNITED STATES PATENTS 1,140,789 Baker May 25, 1915 l,431,426 Robinson Oct. 10, 1922 2,102,055 Brauer Dec. 14, 1937 2,160,515 Pranger May 30, 1939 2,292,345 Arutunof Aug. 11, 1942 2,343,075 Otis Feb. 29, 1944 

